Thickened lubricants



United rates THECKENED LUERHCANTS Everett C. Hughes, Shaker Heights, and Ernest C. Milherger, Maple Heights, Uhio, assignors to The Standard (lil' Company, Cleveland, Ohio, a corporation or 81250 No Drawing. Application October-6, 1954 Serial No. 460,769

4 Claims. (Ci; 25225) This invention relates to an aerogel grease of good high temperature stability and water resistance.

While the word grease has usually been employed to describe an oil thickened with a soap, it is here used ina broader sense to include any thickened lubricant.

Itis generally known that soap-base greases break down at high temperatures, of the order of 300 to 400 F. This breakdown is accompanied by an irreversible change in ithegrease structure, so that upon cooling the grease is observed to have lost its grease-like characteristics. The

aerogel greases usually are far superior to the soap-base greases in stability at high temperatures as the following table shows:

However, after heating at high temperatures some aerogel greases tend to lose consistency upon stirring. This is undesirable because there are many field applications where a grease is agitated or worked while subject to a high temperature and it is important that the grease retain its consistency under these conditions and subsequent thereto.

Accordingly, it is an object of the present invention to provide an aerogel grease having improved stability at high temperatures, particularly after working at high temperatures. I

In accordance with the invention, these objects are accomplished by incorporating a water-miscible or watersoluble ether having at least two polar groups, of which at least one is an other group and one at most is a hydroxyl or amine group, in an aerogel grease composition comprisinga lubricating oil thickened with a non-abrasive, inorganic thickening or gelling agent, and particularly finely-divided silica, a silica aerogen being illustrative. The thickened lubricant so prepared has excellent temperature susceptibility properties.

The grease is also rendered more or less resistant to deterioration by water by incorporating a hydrophobic cationic surface-active Water stabilizer therein in the form of Amine O, 1-fi-hydroxyethyl-2-heptadecenyl imidazoline.

The presence of the ether in an amount to obtain improved high temperature stability does not markedly af feet the consistency of the thickened lubricant, i. e., the

amount of the inorganic gelling agent to impart a given consistency to the thickened lubricant is not materially modified. Furthermore, the inclusion of the ether will 7 not efiect-a change in the consistency of the thickened 2,820,765 Patented Jan. 21, 1958 2 lubricant upon storage. The ether likewise'does' not af feet the water-resistance imparted to the greaseby the hydrophobic cationic surface-active water stabilizing. agent.

Due to the inorganic nature of the gelling agent, the thickened lubricant has excellent storagestability. This is to be contrasted with the heat susceptibility and de terioration of fatty materials 'insoap-'base-greases.

The preparation of the grease is simple and' readily adaptable to continuous operation, as contrasted with the involved grease-making techniques which'are often con sidered in the industry as anart.

The oil stock used in makingthethickened-lubricant may be widely varied, as contrasted with present greasemaking requirements in which the 'oilin manycase's'must meet certain critical specifications.

In addition, the'avoidance of the use of soap permits" the manufacturer to be independent of the fat supply, which is important in periods in which'fat's and soaps are scarce and, many times, of pronounced non-uniformity.

The inorganic gelling agent to be used in making the thickened lubricant in accordance with this invention" may be any inorganic material which forms "a gel with a lubricating oil and which is so finely-.divided as to'be'" non-abrasive. The preferred materials are the aerogels, which may be formed from any material not incompatible with oil, such as silica, alumina, and other gel-'formingi metal oxides. I v

A series of silica aerogel's which can'be used as the in-' organic gelling agent of the invention are marketed"under the trade name Santocel.

Santocel C is prepared from'a'sodium silicate solution" in the following way: The solution is"neut'ralized with sulfuric acid and then allowedto stand until the mixture sets to form a hydrogel. Theby'p'roduct sodium sulfate" is washed out by the repeated washings with water. The continuous water phase in this hydrogelis then replaced by continued washing with alcohol until an alcoge'l' is formed. In order to remove the liquid phase withhut 'a" collapse of the gel structure, the alcogel is placed in an" autoclave which is then heated above the critical temperature of the alcohol and the pressure is allowed to in crease to a point above the critical pressure of'the alcohol.

The vent valve is then opened and the "alcohol allowed'to' escape. Under these conditions, the-silica 'gel'str'ucture" remains practically undisturbed and the liquid phase -of the gel is replaced with air. The material is then 'reduced in particle size by blowing it through a series of pipes containing sharp bends with jets of compressed air.-

Santocel C has a secondary agglomerate particle size of about 3 to 5 microns;

Santocel A is prepared as set forth for Santocel C up." to the point of removal of the product from ureautocla've;

This material is run through a continuous heatingcham v her where it is heated for /2 hour to a temperature of about 1500" F. to eliminate the last traces of volatile material. It is then broken down in a reductionizer-or micronizer to a particle size of about 5 inch in diameter; The-solids content of the original hydrogel used in-preparing Santocel C is approximately 25% higher than that of Santocel-A.

AR is a modification of- A, differing only in that the material is reductionized to about the sameparticlesize as C, approximately 1 to 6 micronsin diameter.

ARD is a modification of-AR,-di-ffering-only. in that ARD is densified by extracting air under-vacuum, -and therefore has a smaller volumethan AR.

AX isanA which has not-been devolatilized. CDv is a C which' has been devolatilized as, set-forthfor A. CDv is reductionizedbefore beingdevolatilizedt CDvR difiers slightly from'CDv in-that-the CDvR- has been devolatilized justatte'nheatingin the autoclave and h. r. l 3 4 then reductionized. It difiers from CDv in that the latter is reductionized before being devolatilized.

The primary differences between the As and the Cs are as follows: V a r .(1) The Cs are prepared from a sodium silicate solutron containing 25% more silica than the As. Therefore,

in general the As are lighter and composed of smaller.

particles than the Cs.

(2) The As have undergone a devolatilization step in their preparation. 1 a p,

The following are the bulk densities of preferred silica aerogels: 7

Density, grams per ml.

AR 0.029- ARD 0.056 to 0.064 c 0.032

similar in physical appearance to the silica aerogel. The.

particle size of the silica is purportedto be 0.01 to 0.05 micron and to be manufactured by burning silicon tetrachloride .and collecting the combustion product on cool plates analogous to the production of carbon'black. The particles are thought to be aggregates or clusters of particles rather than of sponge-like character.

Still another inorganic gelling agent known is Ludox silica which is known as a silica sol, and silica derivatives thereof. It has a particle size of theorder of 0.01 to 0.03

micron.

In preparing thickened lubricants it is necessary to remove the water from the sol and replace it with an voil. This is possible by formulating the lubricant. and removing the water by flash distillation or azeotropic distillation.

No attempt is made to enumerate. all of the inorganic gelling agents which will be suitable, nor to. present examples of all of them since the novel aspects of the invention reside in imparting high temperature stability to the lubricant rather than the use of novelgelling agents, per se.

The lubricating oil to be used in the process may have 50 any lubricating viscosity. It may be raw oil, acid-refined, or solvent-refined, as required for the particular lubricating need.

The nature of the base oil has been found to make little difierence in the relative consistencies of the thickened lubricants and conventionally (acid)- refined oils produce slightly thicker lubricants than solvent-refined. oils. Excellent working stability is obtainedregardless of the type of the base oil. An increase in the viscosity of p the base oil, asmight be expected, brings increased viscosity to the thickened lubricant and minimizes bleeding. The change is relatively small and fairly linear- The viscosity of the oil does not affect the working stability of the lubricant.

The relative proportions of the inorganic gelling agent and the oil will vary somewhat depending upon the desired body in the thickened lubricant, the gelling ability of the inorganic gelling agent and the viscosity of the oil used. It has been noted, for instance, that with the Linde Silica Flour, the lubricants aresomewhat harder, i. e., have a lower penetration than lubricants containing the same weight of Santocel. Lubricants made with lowvi'scosity oils require a somewhat larger amount of the inorganic gelling agent to give a lubricant of the same penetration. The thickened lubricant may vary in consistency from the consistency of a slightly thickened oil to a solid or hydrophobic.

which will be apparent from the theory of the'action 'of' the ether, set forth later. One hydroxyl or amino group semi-solid of grease-like consistency. In general, the amount of the inorganic gelling agent falls within the range of 5 to 20%, and in most cases would fall within the range of 7 to 12%.

The amount of the inorganic gelling agent, as might be expected, affects the consistency of the thickened lubricant in that an increase in its concentration brings a corresponding increase in consistency. The range is fairly linear and the amount of the gelling agent can be selected with relation to the consistency desired in view of the information in the following examples. While ,the difference is slight, the lubricants made with lower concentrations of gelling agent possess better working stability, while lubricants with larger amounts of gelling agent show slightly improved temperature susceptibility characteristics. The bleeding tendencies are decreased by increasing concentrations of the gelling-agent.

In general, the properties of the thickened lubricants are remarkably independent of the composition variables and are not critical. The relative concentration of the gelling agent effects the most significant alteration, particularly with regard to the final consistency of the'prodnot. This permits the manufacture of thickened lubricants having a wide variety of consistencies.

A wide variety of water-miscible or water-soluble ethers (which can be regarded as ethers of polyhydric 1 alcohols having n hydroxyl groups in which n or n-' hydroxyl groups of the polyhydric alcohol are etherified) can be employed in accordance with the invention to improve the high temperature stability of aerogel-base greases. oleaginous in character, cannot be used, because they are The ether must be hydrophilic, for reasons increases the hydrophilic character of the ether.

Theether has from four to twenty carbon atoms and must contain at least two polar groups, of which at least one must be an ether group, one can be an amino group,

and one can be a hydroxyl group. The ether can contain a mixture of ether groups with one amino and/or one hydroxyl group. It may contain as many as ten polar groups, those having two and three polar groups being most available and therefore being preferred. The latter ethers are employed in the examples because of their lowcost and availability. The ethers in addition to one. hydroxyl group and one amino group can contain inert which have been found not: Exemplifying substituents, such as halogen, to reduce the activity of the compounds. compounds within the scope of the invention are monoethyl ether of diethylene glycol, glycerol a-hydroxy di-. methyl ether, ethylene glycol monomethyl ether, monoethyl ether of triethylene glycol, diethylene glycol mono methyl ether, dimethoxy-tetraethylene glycol, polymeric monohydroxyalkyl ethers of polyethers derived by condensation of ethylene oxide or propylene oxide, 'contaiuf diethylene glycol monobutyl ether, diethylene glycol diethyl ether, monomethyl ethylene glycol dimethyl' ether tetraethylene glycol, and B,6'-diaminodiethyl ether. 1

The ether need not be oil-soluble, but should be oiling from two to ten oxide units,

ether of glycerol chlorhydrin,

dispersible. It should have a minimum boiling point of about C. since its primary purpose is to stabilize the grease at high temperatures.

The ether is incorporated in the aerogel-base grease in an amount to impart high temperature stability to the grease. Ordinarily, a concentration of ether ranging from 0.25 to about 1% by weight of the aerogel-base grease gives satisfactory results. There is no reason to employ moreether than is necessary, but excessive amounts do no harm, and amounts up to 5% or even higher have been successfully employed.

Ethers which are water-immiscible, i. e., are

. :higha temperature stabilizer may not. display a :long; life wvhen used continuously at :higlr. =temperatures. r. Abreak- :down in highttemperature stability at-high. temperatures if -.it appears is due to a:decomposition; through-oxidation; of mthe ether stabilize ofthe' inventionnznln *such circumstances, it is desirable to includeiinwthe compositionan .aantioxidant for the ether stabilizer;l fionventional amine antioxidants which are more readily .oxidizedsthanithe Q'EthEI'S of the invention ;canzbe.-.employedlfor athis purpose.

- ,Tetramethyldiaminodiphenylmethane, available under the is azparticularlydesirable anti-:1:

.tr-ade name fCalco in,

oxidant for the others-of the invention. ..Only. small quantities are required, and ordinarily an amount ranging --from 0.1 to about 1% by Weight of the aerogel base'grease is ample. There is no:reason to employ more antioxidant than is necessary to'produce the desiredeffect, but;ex-. 5

.cessive amounts do no harm and amounts up to 5% can be used, if desired.

"The composition is made simply bymixing the inorganicgelling agent, the oil, the etherg the cationic water stabilizer and the antioxidant in any order or manner.

In one:embodiment, the ether, the cationic-water stabilizer and, desirably, the antioxidant, can be incorporated with the inorganic gellingxagent either'bymixing-directly or, if desired, by dissolving them in a volatile hydrocarbon solvent, such as pentane, adding oil, mixing the solution with the inorganic gelling agent, and then" evaporating the solvent.

Generally, the ether, the cationic waterzs'tabilizer and, optionally, the antioxidant are"disper'sed.in 'the oiland .the inorganic gelling agent 'addedvtheretoand mixed therewith. Any simple mixing technique can be employed and, if desired, the mixture can be homogenized in a colloid mill, althoughthis is not necessary.

The composition of the invention is not limited to the oil, gelling agent, cationic Water stabilizer, and ether. Any of the materials conventionally added. tolubricants and greases canbe included. .The expression consisting essentially of as used herein is intended-to refer to the components which are essential to the composition, namely, the oil, the inorganic gelling agent and the ether, and the expression doesnot exclude other components from the composition which do'not render it unsuitable for lubrication, .such materials being, for instance, the cationic water stabilizerythe antioxidantyhi h polymers to modify viscosity or viscosity index,.materialsi to. impart tackiness, lubricating solids such as graphite, antioxidant additives, corrosion inhibitors of various types,.=sulfur, additives to render the lubricant suitable fonuse in gears,'for cutting, grinding, etc.

The following examples illustrate'preferred embodiments of the invention. In the examples, water-resistant thickened lubricants are prepared to show the absence of an effect of the ether on the water resistance of the grease.

, Examples 1' to 4 Aerogel water-resistant greases of the following formulae were made up:

Santocel ARD Amine O Paratac Paraflow 3 Methane base (Oalco MB) Bright stock (78 SSU at 210 F.)

J Ether 8 Formula A is calledzthez-fiAerogel W. R. (Water-Resistant). Base Formula (Example 2) in the table which follows. Example 1 is Formula A, without the Amine O and with 0.8% more of the base oil instead; Formula B is the water-resistant formula modified by addition o'f1% ether in accordance with the invention (and reducing the Bright'stock accordingly) in order to prepare an aerogel :llElg"fGI'.;:th6 time indicated :in the, foliowingitable; the

time being varied so asto approximatethe-final penetrationof'theaerogel water-resistant baseformula. If this time is the same asor longer and/ or if the original-penetration is the sameas or less than that of the base formula, it is evident thattheether hasgeithergnoror a beneficial vThe grease is-prepared for the:-determinationiof' high temperature stability'byplacing approximately. 100 cc; of

grease in a 150 mlwbeaker. The beakers are heatedto the testxtemperature byplacing-them imamaluminurn block furnace. Thisiurnace-consisted of a;solid. block of aluminum heated-by-internal electrical heaters. ksix :holes, each large enough to accommodate a 150 cc. beaker, were drilled in the top'of'th'e 'block, together with a thermocouple, so that a measureof' the temperaturewf the block couldbe'obtainedf in this manner,:six beakers .could'tbe-heated simultaneously. The beakers containing -thegrease were placed in the aluminum furnace-and held .there until theequilibrium temperature of the greasewas "400 F. The samples were stirred at five-minute intervals during'heating. After this the grease wasallowedto-cool to room' temperature overnightand then was stirredvigorously with a spatula. "Thepenetrationof thegrease "was taken before and after heating in the block described in accordance with the Shell Microcone Penetration Test (Institute Spokesman (NLGI), VI, 12, page 1 (1943)).

TABLE H High tempera- Mixing ture stability Ex. time, Immed. No Shell Water N o. Additive min- Shell eypenetration stabilutes pen. eles ity Initial Final l- Aerogelbase 40 159 5 157 202 None. 2 AformrlilwaAR 40 5 157 202 Do. 30 4 171 267 Good. giff a i 159 i 4 171 267 Do. 3. Dimethoxy- 3 0 7 126 219 Do. 1: t h lt. f fig g -30 121 i 7 178 210 Do. 4 do 30 '3 14.0 None.

No Amine "0: contains 0.8% more base oil instead. 2 Using a. two-quart sample.

.andwater stabilization.

Examples 5 to 15 8. beaker. 0.8% Amine was added, and 1% of the ether additive-was incorporated in the base oil. The oil mix was heated to 130 F. while being mixed with a'Light- 1 nin stirrer, and 8% Santocel ARD was mixed in with 1 Tested using a Z-quart sample.

and triethylene glycol monoethylether are most effective,

but even the least eifective of the additives gives a significant improvement in high temperature stability. The supplemental data in which two-quart sampleswere tested for Examples 8, ll, 12.,and 15 shows that the ethers' are eflective for both high temperature and water' sta'bilization,' even in largerscale preparations.

Examples 16 to 25 Anumeral of aerogel greases were prepared as fol- :lows:- A fixed quantity of oil v(78 SSU at 210 F. solventextracted Bright stock) was weighed 01111111011400 ml.

A B 5 hand stirring. The resulting grease was allowed to stand. overnight. An original penetration was then obtained P t PC m using the Shell Microcone Penetration Test and the grease santocel 31, was then subjected to the block test. Grease samples ex- Amine O g-g g-g hibiting some degree of high temperature stability were 533 3; 10 cycled three or four times. Each sample was tested also Methane base (Ga n 5 5 for water stability and given a visual rating for consistency 9.2 88.2 p aic stock (78 SSU at 210 F1 K n 8 1.0 whlle at The ether additives tested included monohydroxy and 1 1.5.hydmxyethypgheptadeeenyfimidamum 1 nonhydroxy ethers. Several monohydric alcohols were ini1; is gib l l y e ne po gggeg s rgg bg t g gg y Company, cluded to compare the results obtainable. Data from these 8.11 m 0 11 E 111 1 i A Friedel flrafts reaction product, useful as a pour point tests are glven 111 the followmg tabledept'essant and solo by the Enjay Company, Inc. a ABLE Iv '-Tetrarnethyldiaminodtphenylmethane. I g j 7 Formula A is Example 5 in the table which follows. u 1 n 1 Formula B is thewater-resistant formula of Formula A, Additive p e io s Water modified by addition of 1% ether in accordance with the m invention, reducing the Bright stock accordingly, in order o e 1 o 2 3 4 to prepare an aerogel grease which is not only-waterresistant but also stable at high temperatures. 7 16-... 11 1 1 R- base 139 200 226 F In preparing these greases, the Amine O and the ether 25 to betested were dissolved ina stock solution of the base Monolwdric alcohol? oil containing the other components. The Santocel was added to the solution and completely wetted by stirring. ig- D The grease was prepared at 95 F. by mixing for approxi- I mately twenty to thirty minutes, the time-being adjusted to approximate the original pentration of Formula A; Ether, 1

The penetration of the grease was takenfbefore and :after heating in the block described in Example 1 in *acg fifi i fl 150 183 200 208 cordance with the Shell MicropenetratiomTest. After methylene glycol mono- 124 6 169 6 189 Do- 'th dt hdb tk r r 1- a 1 I e a h F a BI! P 0111' suicesslve y d l h 24 Diatlgyllertte glycol mono- 199 199 189 215 130. .average c ange 1n penetratton per eye e was note .1 e u y e "water stability of thegreases was also determined. The "7' i iiiif 157 168 185 193 .:following results were obtained:

' TABLE 111 Block" test, Shell pens. Ex. Additive Percent ApenJ Water No. cycle stability Orig. 1st 2nd 7 3rd 4th (a) 00mm with Ammc o'i' 139 200' 226 43.5 Good.

(b) do 171 267 24 Do. Ethylene glycol monoethyl ether.-- .0 183 200 208 19 Do. 7 Diethylene glycol monoethyl ether. 1. 0 149 153 183 11 Diethylene glycol monoethyl other 1.0 124 160 169 186 189 16 Do. 1 do 1 t, 2. 0 187 200 1.9 Do. 1 Diethylene glycol monobutyl ether. 1. 0 140 199 197 215 25 D0. Diethyleue glycol monohexyl ether. 1. 0 I 150 174 208 204 18 Diethylenc glycol diethyl ether 1. 0 123 146 176 190 22 (0)... do 2.0 193 220 4.3 12 (a)-.- Diethylene glycol dibutyl ethen. 1.0 V 123 154 188 193 23 (D)... de 1 2.0 182 214 s 13 Triethylene glycol monoetl1ylether 1; 0 154 173 191 198 15 14 Tetraethylene glycol dimethyl ether 1. 0' 129 157 168 193 16 D0. {(11)... Tetraethylene glycol dibutyl other." 7 1. O 138 154 192 199 20 Y (b) do 2.0 193 240 11.3

Without exception, the five monohydric alcohols tested were unsatisfactory under high temperature conditions.

The importance of an ether linkage is shown'bycomparison of these results with Examples 22, 23: 211d '24.. .The

. initial penetrations for diethylene glycol monoethyl ether" and dimethoxytetraethylene glycol (Examples 23 and 25) are lower than that of the control grease, and indic'ate that these compounds have no deleterious effect on grease yield. The other ethers tested, Examples 22 and 24, also exert a stabilizing efiect at high temperatures. V i

Examples 26 and 27 The test greases were prepared as outlined in the preceding Examples 16 to 25. The results are given in the following table:

It is evident that the ethers are capable of increasing high temperature stability, even when a heavy base oil is employed.

In the examples, the high temperature stability of the aerogel greases is tested by heating the greases to 400 F. This is an extreme test, inasmuch as the highest temperature to which a grease is subjected under even extraordinary conditions of use is about 300 F., but it was adopted as a suitable test standard by which to measure the high temperature stability of the greases because a grease stable at 400 F. will definitely have the stability necessary to withstand heating to 300 F. It will be understood that for normal purposes an aerogel grease need not be stable at temperatures above about 300 F., and that the greases of the invention at least meet this requirement. Where the term high temperature stability is used, it will be understood to mean that the aerogel grease is stable at at least 300 F.

The following hypothesis is given as a partial explanation of the reason to which is attributed the action of the ether in improving the high temperature resistance of aerogel grease, but the invention is not to be bound thereby.

Silica aerogels are known to be in the form of an extremely finely-divided material and it is thought that it is capable of forming a colloidal structure in the oil vehicle employed in an aerogel grease. Mixing or stirring in formulating the grease serves to disperse the secondary aerogel agglomerates throughout the body of the oil. The aerogel occupies a greater volume than the liquid oil vehicle, and because of this it is probable that the colloidal structure is aided somewhat by a close packing of the solid silica gel particles perhaps with mechanical interlocking. It is thought that the basis of the structure is a tying together of the various silica aerogel particles by hydrogen bonding between hydroxyl groups which remain attached to individual silicon atoms in the silica gel molecule.

In setting up the colloidal grease structure, it is postulated that the distances between adjacent hydroxyl groups on different particles of silica aerogel may be too great in some circumstances to form a binding, attractive force between particles. In this event, water, which is always present in the aerogel structure, serves to bridge the gap between adjacent particles through hydrogen bonding between the compound and the hydroxyl groups on the adjacent silica aerogel particles. Thus the Water in eitect aids in setting up the colloidal grease structure, and may also link it together, at least in part.

When the grease under static conditions is submitted to temperatures high enough to volatilize the water no apparent efiect is noticed at first, for there is no force to disarrange the structure. Consequently, penetration vs. temperature curves indicate that aerogel greases have excellent high temperature performance with a very low increase in consistency as the temperature is increased. However, when this static state is disturbed by stirring, the structure can and does collapse, due to the absence of the water which has been volatilized and which formerly served as the connecting links between adjoining silica particles. In consequence, the structure passes from a gel state to a colloidal sol state. This explains why the transformation of the heated aerogel grease from a greaselike condition to a soupy condition occurs only after stirring and why stirring thus brings about an apparently irreversible gel-to-sol transformation. This transformation may be reversed to some extent by adding Water to the soupy grease, tending to substantiate this hypothesis, but it is not possible to return the grease to its original condition.

Thus, on the basis of this hypothesis, incorporation in the grease, in accordance with the invention, of an ether which has at least two polar groups and which is not volatile at the temperatures to which the grease may be subjected leads to a partial or complete displacement of water in the aerogel by ether, possibly before and in any event at the time water is volatilized at an elevated temperature. The involatility of the ether prevents its loss during heating and thus prevents destruction of the colloidal grease structure when the aerogel grease is stirred after it has been heated to high temperatures. It is also apparent from this that a hydrophobic ether which is immiscible with water could not function in this way because it could not act as a substitute for Water in the hydrophilic gel structure.

This application is a continuation-in-part of applications Serial Nos. 119,752, filed October 5, 1949 and 253,984, filed October 30, 1951, both now abandoned.

We claim:

1. A water-resistant thickened lubricant of good temperature susceptibility properties, consisting essentially of a mineral lubricating oil of lubricating viscosity, an inorganic Water-sensitive gelling agent imparting a greaselike consistency to the oil upon addition thereto, l-B-hydroxyethyl-Z-heptadecenyl imidazoline imparting stability against deterioration by water, and a water-soluble ether having a boiling point of at least C. at atmospheric pressure and having at least two polar groups and imparting high temperature stability, at least one of which is an ether group, and one at most is selected from the group consisting of hydroxyl and amino groups.

2. A water-resistant thickened lubricant of good temperature susceptibility properties in accordance with claim 1 wherein the ether is diethylene glycol monoethyl ether.

3. A Water-resistant thickened lubricant of good temperature susceptibility properties in accordance with claim 1 wherein the ether is dirnethoxytetraethylene glycol.

4. A water-resistant thickened lubricant of good temperature susceptibility properties in accordance with claim 1 wherein the ether is ethylene glycol monoethyl ether.

References Cited in the file of this patent UNITED STATES PATENTS 2,531,440 Jordan Nov. 28, 1950 2,554,222 Stross May 23, 1951 2,563,606 Kimberlin et al. Aug. 7, 1951 2,573,650 Peterson Oct. 30, 1951 2,662,056 McCarthy Dec. 8, 1953 2,676,148 Iler Apr. 20, 1954 2,711,393 Hughes et al. June 21, 1955 

1. A WATER-RESISTANT THICKENED LUBRICANT OF GOOD TEMPERATURE SUSCEPTIBILITY PROPERTIES, CONSISTING ESSENTIALLY OF A MINERAL LUBRICATING OIL VISCOSITY, AN INORGANIC WATER-SENSITIVE GELLING AGENT IMPARTING A GREASELIKE CONSISTENCY TO THE OIL UPON ADDITION THERETO, 1-B-HYDROXYETHYL-2-HEPTADECENYL IMIDAZOLINE IMPARTING STABILITY AGAINST DETERIORATION BY WATER, AND A WATER-SOLUBLE ETHER HAVING A BOILING POINT OF AT LEAST 150*C. AT ATMOSPHERIC PRESSURE AND HAVING AT LEAST TWO POLAR GROUPS AND IMPARTING HIGH TEMPERATURE STABILITY AT LEAST ONE OF WHICH IS AN ETHER GROUP, AND ONE AT MOST IS SELECTED FROM THE GROUP CONSISTING OF HYDROXYL AND AMINO GROUPS. 